Gasket for plate heat exchanger

Abstract

A gasket for a plate heat exchanger has a strip of metal fastened to one heat exchanger plate and bridging at least 50% but not the entire distance between that plate and an adjacent plate, and a layer of a material of lesser hardness than the metal attached to the metal strip and bridging the remaining distance between the plates.

We claim: 
     
       1. In combination with a plate heat exchanger having a plurality of heat exchange plates, there being spaces between adjacent plates in the heat exchanger defining flow passages for heat exchange media, a gasket applied between two adjacent plates characterized in that the gasket (4) comprises a strip (5) of metal, fastened to one of the plates (1, 2) and bridging at least 50% of but not the whole distance between the plates, and a layer (7) made of a material with a lesser hardness than the metal and applied onto a surface of the metal strip directed towards the other of said two plates (1, 2), said layer (7) bridging the remaining part of said distance between the plates. 
     
     
       2. The combination of claim 1, wherein each plate has a gasket groove (6, 8) on one side of said plate, said groove forming a ridge on the opposite side of said plate, characterized in that the metal strip (5) is fastened to said one of said plates (1, 2) at the bottom of its gasket groove (6, 8). 
     
     
       3. The combination of claim 1, wherein each plate has a gasket groove (6, 8) on its side, forming a ridge on its opposite side, characterized in that the metal strip (5) is fastened to said one of the plates (1, 2) at the top of its ridge. 
     
     
       4. The combination of claim 2, characterized in that the metal strip (5) extends along the whole of the gasket groove (6, 8). 
     
     
       5. The combination of claim 1, characterized in that the metal strip (5) is made of stainless steel. 
     
     
       6. The combination of claim 1, characterized in that the metal strip (5) is fastened to said one of the plates along its whole extension by means of welding. 
     
     
       7. The combination of claim 1, characterized in that said layer (7) is composed of a graphite material. 
     
     
       8. The combination of claim 1, characterized in that said layer (7) is composed of a plastics material. 
     
     
       9. The combination of claim 3, characterized in that the metal strip (5) extends along the whole of the gasket groove (6, 8).